During start-up acceleration of a permanent magnet alternating current (AC) electric motor in accordance with conventional algorithms that estimate the rotor position based on the voltage and current without using the rotor position or speed sensor (i.e., in accordance with “sensorless algorithms”), a current vector position is forced to increase with a fixed profile and a position of a rotor of the motor is expected to lag behind the current vector position, while a current amplitude is controlled to be constant. If there is a big load torque required during the start up sequence, then current is set high enough to generate the required startup torque, while in the light load condition, the current introduces transient oscillations of the angle difference between the current vector and the rotor position in the motor. These transient oscillations generate undesired mechanical oscillations in the permanent magnet AC motor during startup thereof.
Accordingly, it is desirable to provide a method and apparatus for start-up of a permanent magnet AC motor in an electric motor system reduced mechanical oscillations. In addition, it is desirable to prevent current overshoot during a sensorless start up of a permanent magnet AC motor. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.